I have 2 Mice and -had- one Dragonfly (ss/se, friend of mine bought it out of my pocket). I played with the 2 of them side by side around work for about a week. The flat ground, serrated, distal tapered blade of the Dragonfly cuts cardboard like a laser. The Dragonfly is also flatter and smaller, and many will find it easier to carry in dress clothes.
That said, I like the Mouse better. I noticed that outside of work, I would carry the Mouse by itself, but would not carry the Dragonfly by itself. The Mouse feels very secure and sturdy in my hand, and I think that I would have to try hard to break it. This is not meant as a slam on the Dragonfly, but I think of it as a light duty office/gents folder and the Mouse as a small outdoors/hunting knife.
I have all the Spydie Wegners, and find that 90% of the time I carry the C48 or the Mouse, and the C49 stays home.
I paid full retail for my first Mouse, and although I managed to buy my second one on here used, I would have payed retail for it too if I had been forced to.